Improve admin operations landing page

doc/administration/operations/index.md

@@ -13,6 +13,9 @@ Keep your GitLab instance up and running smoothly.
   you have been running a large GitLab server (thousands of users) since before
   GitLab 7.3 we recommend cleaning up stale sessions to compact the Redis
   database after you upgrade to GitLab 7.3.
+- [Rake tasks](../../raketasks/README.md): Tasks for common administration and operational processes such as
+  [cleaning up unneeded items from GitLab instance](../../raketasks/cleanup.md), integrity checks,
+  and more.
 - [Moving repositories](moving_repositories.md): Moving all repositories managed
   by GitLab to another file system or another server.
 - [Sidekiq MemoryKiller](sidekiq_memory_killer.md): Configure Sidekiq MemoryKiller
@@ -28,6 +31,8 @@ Keep your GitLab instance up and running smoothly.
   performance can have a big impact on GitLab performance, especially for actions
   that read or write Git repositories. This information will help benchmark
   filesystem performance against known good and bad real-world systems.
+- [The Rails Console](rails_console.md): Provides a way to interact with your GitLab instance from the command line.
+  Used for troubleshooting a problem or retrieving some data that can only be done through direct access to GitLab.
 - [ChatOps Scripts](https://gitlab.com/gitlab-com/chatops): The GitLab.com Infrastructure team uses this repository to house
   common ChatOps scripts they use to troubleshoot and maintain the production instance of GitLab.com.
   These scripts are likely useful to administrators of GitLab instances of all sizes.